In-Depth Study of Different Magnetorheological Fluid Properties Under Different Operating Parameters, and in Presence of Organic Additives

The fast and reversible structural reorganization of magnetic particles in a non-magnetic carrier liquid on the application of a magnetic field makes magnetorheological fluids (MRFs) a valuable material for various damping systems. As MRFs form chains, MRFs transit from a liquid state to a solid-like state exhibiting an increase in viscosity. Since MRF discovery, commercialization, and enhancement of MRF performance in earthquake dampers, is the focus of interest to protect 10k lives lost annually due to earthquakes. As earthquake dampers, MRFs in a damper will convert mechanical vibration energy to heat energy while forming MRF chain structures controlled by a magnetic field thereby reducing the impact of earthquake vibrations/shock and limiting the movement of a building. Using MRFs has the advantages of low energy consumption, fast response, adjustable damping force, and broad temperature range. MRF damper performance is a strong function of MRF fluid performance itself, pushing the need to understand MRF properties. Additionally, the use of MRFs in earthquake dampers will involve the storage of MRFs for a long time without performance degradation, ensuring MRF colloidal stability and reusability. The work presented here will focus on developing an in-depth understanding of MRF rheology as a function of varying MRF formulation, and various operating parameters simultaneously. The results demonstrated a strong influence of magnetic particle concentration and operating temperature on MRF rheology. The obtained results are used in developing n-alkanethiol surface coating and elastic SEBS bead additives to enhance MRF colloidal stability (measured using an in-built setup) and alter viscoelastic properties. respectively. Finally, MRF chain characteristics (the strength, speed, and structure of MRF chains) were also studied as a function of both MRF rheology and compared at a microscopic level. Understanding the MRF properties and chain formation will ease the control of MRFs in real-time applications and the designing of MRF damping systems. Additionally, developed coatings and additives will enhance MRF colloidal stability and reusability respectively that can aid in commercialization of MRFs in earthquake damping systems.

Grantor dc:publisher

University of Alabama Libraries

Year dc:date.issued

2024

Author dc:creator

• Thiagarajan, Sandhiya

Advisor dc:contributor.advisor

• Koh, Amanda S

Contributors dc:contributor

• Brazel, Christopher S
• Bara, Jason E
• Song, Wei
• Bao, Yuping

• MRFs
• response time
• rheology
• settling
• viscoelasticity

Statement dc:rights

• All rights reserved by the author unless otherwise indicated.

Language dc:language.iso

en_US, English

Dc Identifier Other

1053744

OAI identifier oai:identifier

oai:ir.ua.edu:123456789/13845